The present invention relates to a method and a device for establishing a geometry of a container for packaging in particular a flowable medium.
Systems for establishing a surface or even the contour of objects are principally known. For example, there are tactile sensors which establish individual surface points of an object by mechanical scanning. Furthermore, it is known, for example, to use camera systems in particular for establishing an external contour of an object. Here, optically detectable two- or three-dimensional measuring points are detected by means of the camera system and transformed in such a manner that the system generates a corresponding image and consequently a two- or three-dimensional contour of the scanned object. For example, it is also possible that a light source for generating a light pattern on a surface of the object to be measured serves as a scanning device, wherein said light pattern is reflected by the surface and detected by a camera of the system. Such systems primarily serve for measuring an external contour of an object having a primarily radiation-reflecting surface. If the light radiation would be largely absorbed by the material of the object to be measured, this would result in an inaccurate or incorrect establishment of the external contour. In the worst case, measuring and establishing the external contour would not be possible at all. For example, measuring or establishing the external contour of an object, in addition to monitoring the production process of the object itself, can also serve for enabling the possibility to set up a subsequent machining process for machining the object in consideration of the contour and configuration of the object.
However, not only the external contour, but also the configuration of the inner contour and/or the dimensions of the wall thickness, in particular of a container such as, for example, a bottle or a food packaging, are values which are to be considered in the production process of the container itself or the bottling or filling process of the container, or in further tests such as, e.g., durability tests. Specifically in the case of durability tests, it is a disadvantage that the container in which the particularly liquid medium is disposed, for example, in the form of food or a beverage, often has to be opened or destroyed for the test. Non-destructive testing normally is performed using optical sensors. In particular for establishing the wall thickness and/or the external contour, it is basically known to use light and camera systems which are arranged along a production path for producing or treating containers in order to scan and measure different regions of the container in a time-consuming and cost-intensive manner so as to be able to establish individual values with regard to the geometry of the container. Accordingly, measuring a container is not only time-consuming, but also cost-intensive and prone to error due to the use of additional measuring apparatuses.